The present invention relates to loading assemblies used for testing portions of a vehicle. More particularly, the present invention relates to a loading assembly for applying a lateral force to a vehicle spindle to emulate the rolling radius of a tire assembly and for applying steer moments and camber moments to the vehicle spindle.
Many test fixtures have been advanced to apply forces and moments to a vehicle spindle in order to simulate driving or road conditions. These test fixtures often include separate actuators to apply substantially independent vertical, longitudinal and lateral forces as well as a braking moments to the vehicle spindle. U.S. Pat. Nos. 4,733,558 and 5,083,453 disclose two such test fixtures.
Commonly, the test fixtures include a wheel adapter housing that is mounted to the vehicle spindle. Two vertical struts are joined to the perimeter of the wheel adapter housing and are used to transfer the longitudinal forces, the vertical forces and the braking moments to the vehicle spindle. A center downwardly projecting tang located between the vertical struts and also joined to the perimeter of the wheel adapter housing is joined to a lateral strut, which is used to transmit lateral force developed from an actuator.
Although the above-identified test fixtures are quite capable of applying longitudinal forces, vertical forces, lateral forces and braking moments to the vehicle spindle, adaptation of the test fixtures in order to apply either steer moments or camber moments to the vehicle spindle is not easy. For example, severe clearance problems with the vertical struts and/or the vehicle fender well sheet metal are encountered as the braking moment is applied if struts are located far from the perimeter edge of the wheel adapter housing. However, use of a single pivot connection of the lateral strut to the tang is also undesirable since the wheel adapter housing does not accurately emulate the rolling radius of the actual tire assembly that is mounted to the spindle particularly when the spindle is subjected to large vertical displacements.